1. Field of the Invention
The present invention relates to a flat panel audio output apparatus and a video/audio output apparatus, and, more particularly, to a flat panel audio output apparatus and a video/audio output apparatus which can output a sound according to a plurality of audio channels or a plurality of frequency bands.
2. Description of the Related Art
Conventionally, a cone-type speaker has been widely used in outputting a sound. The cone-type speaker generally comprises a cone made of paper, plastic, aluminum, or the like; a flexible surround surrounding the rim of the cone; and a corrugated spider circumferentially surrounding the vertex of the cone.
Recently, there has been developed a flat panel audio output apparatus outputting a sound through a flat panel. Here, the flat panel audio output apparatus makes a sound through a flat panel vibrated (or excited) by an exciter transforming an electric signal into a mechanical vibration.
Thus, the flat panel audio output apparatus comprises the flat panel making a sound, and the exciter placed on the flat panel and vibrating the flat panel.
Generally, in the flat panel audio output apparatus, two exciters, corresponding to two audio channels for a stereophonic sound, are placed on a single flat panel. Therefore, each exciter vibrates the flat panel on the basis of an electrical audio signal outputted from each respective audio channel, and the flat panel is vibrated by both exciters corresponding to the two audio channels, thereby making a sound.
However, in the conventional flat panel audio output apparatus, because the respective exciters corresponding to the audio channels are provided in the single flat panel in order to vibrate the single flat panel, interference arises between vibrations caused by the respective exciters corresponding to the two audio channels.
FIG. 1 illustrates interference between vibrations due to two audio channels in a conventional flat panel audio output apparatus 100. On a flat panel 110 of FIG. 1, ‘Δ’ indicates a sound position due to the vibration caused by a left exciter 120a, and ‘x’ indicates a sound position due to the vibration caused by a right exciter 120b. 
Here, the sound positions of the flat panel 110 vibrated by the respective exciters 120a and 120b are distributed on the flat panel 110. Therefore, the flat panel 110 has an interference area A where interference arises between the vibrations caused by the respective exciters 120a and 120b. 
The interference between the audio channels deteriorates the quality of a sound outputted from the flat panel audio output apparatus 100. Accordingly, there is a need to eliminate the interference between the audio channels of the flat panel audio output apparatus 100.
Further, if an audio output apparatus such as a loudspeaker can output sounds corresponding to a low-pitched sound, a middle-pitched sound and a high-pitched sound, i.e., corresponding to frequency bands without interference with regard to the same channel, sound quality will be more enhanced.